Reference sphere detecting device, reference sphere position detecting device, and three-dimensional-coordinate measuring device

Abstract

A reference sphere detecting device used for a reference sphere position detecting device comprises an optical unit having a laser light source, a collective lens for collecting light from the laser light source and irradiating the light to a reference sphere positioned at or near a front focal position, a first image pickup device for receiving and detecting reflected light from the reference sphere, the first image pickup device being disposed at a rear focal position of the collective lens; driving units for rotationally moving the optical unit about a reference point; and a control unit for controlling the driving units on the basis of the position at which the reflected light is received and rotationally moving the optical unit so that the reflected light reaches a predetermined reference position of the first image pickup device.

1. A reference object detecting device comprising:
 an optical unit including a collective lens which collects light from a reference object without any optical element having power arranged between the reference object and the collective lens, and an image pickup unit arranged at or near a rear focal position of the collective lens; 
 a driving unit which rotationally moves the optical unit about a reference point; and 
 a control unit which controls the driving unit to rotationally move the optical unit, and thereby rotationally move both the collective lens and the image pickup unit, on the basis of a position where the collected light is received on the image pickup unit. 
 
     
     
       2. The reference object detecting device according to  claim 1 , wherein
 the optical unit comprises a light source which emits light; and 
 the reference object is provided with a substantially spherical surface, and the light emitted by the light source is irradiated via the collective lens toward the substantially spherical surface and is thereby reflected from the substantially spherical surface and then collected by the collective lens as said collected light. 
 
     
     
       3. The reference object detecting device according to  claim 2 , wherein a focal length of the collective lens and a radius of the substantially spherical surface are determined based on resolution of the image pickup unit and a required detection precision relating to an amount of offset from a center of the substantially spherical surface. 
     
     
       4. The reference object detecting device according to  claim 2 , wherein the control unit controls the driving unit to rotationally move the optical unit to adjust for an offset of the emitted light from an optical axis of the emitted light that would cause the emitted light to pass through a center of a sphere having the substantially spherical surface. 
     
     
       5. The reference object detecting device according to  claim 4 , wherein the control unit controls the driving unit to rotationally move the optical unit to adjust for the offset so that the collected light is received at a center point of the image pickup unit. 
     
     
       6. The reference object detecting device according to  claim 1 , wherein the control unit controls the driving unit to rotationally move the optical unit to control the position where the collected light is received on the image pickup unit so that the collected light reaches a predetermined reference position on the image pickup unit. 
     
     
       7. The reference object detecting device according to  claim 1 , wherein
 the optical unit has an imaging lens and an image detector which detects an image of the reference object imaged by the imaging lens; and 
 the control unit controls the driving unit to rotationally move the optical unit on the basis of the image of the reference object detected by the image detector so that the collected light is incident on the image pickup unit. 
 
     
     
       8. The reference object detecting device according to  claim 1 , wherein the driving unit is configured so as to rotationally move the optical unit in a horizontal direction and a vertical direction. 
     
     
       9. The reference object detecting device according to  claim 1 , comprising an angle detector which detects an angle of the optical unit in a horizontal direction and a vertical direction. 
     
     
       10. The reference object detecting device according to  claim 1 , wherein the optical unit further comprises an interference optical system for length measurement. 
     
     
       11. An apparatus comprising a first reference object detecting device according to  claim 1  and a second reference object detecting device according to  claim 1 , wherein
 the first and second reference object detecting devices are separated by a predetermined interval, and 
 the apparatus uses the first and second reference object detecting devices to measure three-dimensional coordinates of a center of a reference object based on the predetermined interval and an azimuth angle and an elevation angle measured by the first and second reference object detecting devices. 
 
     
     
       12. A three-dimensional-coordinate measuring device for measuring an object, comprising:
 reference objects on the surface of the object; and 
 at least two or more apparatuses according to  claim 11  so as to correspond, respectively, to the number of the reference objects, 
 wherein three-dimensional coordinates of centers of the reference objects are measured by the corresponding apparatus, respectively, and a position and orientation of the object to be measured is detected based on the measured three-dimensional coordinates. 
 
     
     
       13. The reference object detecting device according to  claim 1 , wherein the control unit controls the driving unit to rotationally move the optical unit so that the collected light is received at a center point of the image pickup unit. 
     
     
       14. An apparatus comprising:
 an optical unit including a light source which emits a light, a collective lens which irradiates the emitted light toward a substantially spherical surface so that the emitted light reflects off the substantially spherical surface and which collects the reflected light, and an image pickup unit which receives the collected light; and 
 a control unit which calculates an offset of the emitted light from an optical axis of the emitted light that would cause the emitted light to pass through a center of a sphere having the substantially spherical surface, and causes the optical unit to be moved, and thereby causes the light source, the collective lens and the image pickup unit to be moved, to adjust for the calculated offset. 
 
     
     
       15. The apparatus according to  claim 14 , wherein the control unit causes the optical unit to be moved to adjust for the offset so that the collected light is received at a center point of the image pickup unit. 
     
     
       16. The apparatus according to  claim 15 , wherein the substantially spherical surface is a surface of a moving reference object. 
     
     
       17. The apparatus according to  claim 14 , wherein the substantially spherical surface is a surface of a moving reference object. 
     
     
       18. A reference object detecting device comprising:
 an optical unit including a collective lens which collects light from a moving reference object, and an image pickup unit which receives the collected light via the collective lens; 
 a driving unit which rotationally moves the optical unit about a reference point; and 
 a control unit which controls the driving unit to rotationally move the optical unit, and thereby rotationally move both the collective lens and the image pickup unit, on the basis of a position where the collected light is received on the image pickup unit, wherein
 the optical unit has an imaging lens and an image detector which detects an image of the reference object imaged by the imaging lens, and 
 the control unit controls the driving unit to rotationally move the optical unit on the basis of the image of the reference object detected by the image detector so that the collected light is incident on the image pickup unit. 
 
 
     
     
       19. An apparatus comprising:
 first and second reference object detecting devices, each comprising:
 an optical unit including a collective lens which collects light from a moving reference object, and an image pickup unit which receives the collected light via the collective lens, 
 a driving unit which rotationally moves the optical unit about a reference point, and 
 a control unit which controls the driving unit to rotationally move the optical unit on the basis of a position where the collected light is received on the image pickup unit, wherein 
 
 the first and second reference object detecting devices are separated by a predetermined interval, and 
 the apparatus uses the first and second reference object detecting devices to measure three-dimensional coordinates of a center of a reference object based on the predetermined interval and an azimuth angle and an elevation angle measured by the first and second reference object detecting devices. 
 
     
     
       20. An apparatus comprising:
 an optical unit including a collective lens which collects light from a reference object without any optical element having power arranged between the reference object and the collective lens, and an image pickup unit arranged at or near a rear focal position of the collective lens so that the collected light is received on the image pickup unit; and 
 a control unit which rotationally moves the optical unit, and thereby rotationally moves both the collective lens and the image pickup unit, on the basis of a position where the collected light is received on the image pickup unit. 
 
     
     
       21. An apparatus as in  claim 20 , wherein
 the collected light received on the image pickup unit is not an image of the reference object. 
 
     
     
       22. An apparatus as in  claim 21 , wherein:
 the optical unit includes an additional image pickup unit which detects an image of the reference object, and 
 the control unit adjusts positioning of the optical unit in accordance with the detected image. 
 
     
     
       23. An apparatus comprising:
 an optical unit including a collective lens which collects light from a reference object without any optical element having power arranged between the reference object and the collective lens, and an image pickup unit arranged at or near a rear focal position of the collective lens so that the collected light is received on the image pickup unit; and 
 means for rotationally moving the optical unit, and thereby rotationally moving both the collective lens and the image pickup unit, on the basis of a position where the collected light is received on the image pickup unit.